The British Navy ship Tamar has found the navigation record book from New Zealand's sunken survey ship, HMNZS Manawanui.

The British warship has been on patrol off the coast of Upolu, in Samoa, where the Manawanui struck a reef and sank nearly two weeks ago.

Crew on board the Tamar have been searching for items from the wreck and monitoring oil pollution.

The navigation record book is likely to be an important piece of evidence in the Court of Inquiry into the Manawanui's sinking.

The Defence Force said it had no details about how the document was recovered.

Meanwhile, another New Zealand Navy ship, HMNZS Canterbury, had arrived in Apia carrying specialist equipment, the Defence Force said in a statement.

"Three containers from the ship remain out on the reef. The team has emptied one of the containers and one was already empty."

The third one holds 3000kg of food but is not watertight.

The containers are damaged and are being moved by tides and swells.

The Defence Force is working with a local contractor to float the three metre containers and tow them to shore.

It's expected to take at least three days to remove them, depending on the weather.

The Defence Force was conducting daily beach surveys, while Air Force drones had been deployed to assist with shoreline surveys, the statement said.

"The New Zealand Defence Force (NZDF) task group ashore and Maritime NZ have confirmed that so far no pollution has been found on the shorelines, nor any deceased wildlife."

An Air Force Poseidon had also been used to conduct surveillance flights to aid in assessing the site of the sinking.